Lanthanide ions promote the hydrolysis of 2,3-bisphosphoglycerate.

Abstract

The 31P NMR studies showed that lanthanide ions promote the site-specific hydrolysis of 2,3-Bisphosphoglycerate (BPG) at pH 7.4 by cleaving the 2' phosphomonoester bond. The effect of fourteen trivalent lanthanide ions and Sc3+, and Y3+ were compared by the percentage of hydrolysis obtained by determining the inorganic phosphate produced. All the trivalent lanthanide ions promote the hydrolysis, but Sc3+ not. Among them, Ce3+ affects the reaction mostly. This was mainly attributed to the autooxidation of Ce3+ to Ce4+, since the promoting effect of Ce3+ is related to the increasing Ce4+ amount in the solution and depressed by adding sulphite. Ce4+ promotes the hydrolysis more efficiently than Ce3+ do. The pseudo first-order rate constant for the hydrolysis of BPG by Ce(SO4)2 (18.7 mM) at pH 1 and pH 2, 37 degrees C is 3.1 h(-1) and 0.65 h(-1) respectively. A mechanism with a hydroxo species as reactive intermediate was proposed for the trivalent lanthanide ions. The site-specificity was explainable by this mechanism.